1. Field of the Exemplary Embodiments
The exemplary embodiments described herein relate to semiconductor workpiece processing tools and, more particularly, to processing tools having a linear arrangement.
2. Brief Description of Related Developments
One of the factors affecting consumer desire for new electronic devices naturally is the price of the device. Conversely, if the cost, and hence the price of new electronic devices can be lowered, it would appear that a beneficial effect would be achieved in consumer desires for new electronic devices. A significant portion of the manufacturing costs for electronic devices is the cost of producing the electronics which starts with the manufacturing and processing of semi-conductor substrates such as used in manufacturing electronic components, or panels used for making displays. The cost of processing substrates is affected in part by the cost of the processing apparatus, the cost of the facilities in which the processing apparatus are housed, and in large part by the throughput of the processing apparatus (which has significant impact on unit price). As can be immediately realized, the size of the processing apparatus itself impacts all of the aforementioned factors. However, it appears that conventional processing apparatus have reached a dead end with respect to size reduction. Moreover, conventional processing apparatus appear to have reached a limit with respect to increasing throughput per unit. For example, conventional processing apparatus may use a radial processing module arrangement. A schematic plan view of a conventional substrate processing apparatus is shown in FIG. 9. As can been seen, the processing modules of the apparatus in FIG. 9 are placed radially around the transport chamber of the processing apparatus. The transport apparatus, which is a conventional two or three axis of movement apparatus (e.g. Z, θ, T Axis) is centrally located in the transport chamber to transport substrates between processing modules. As can be realized from FIG. 9, throughput of the conventional processing apparatus is limited by the handling rate of the transport apparatus. In other words, throughput cannot be increased with the conventional apparatus by merely adding processing modules to the apparatus, because once the transport apparatus reaches a handling rate peak, this becomes the controlling factor for throughput. The apparatus of the present invention overcome the problems of the prior art as will be described further below.